This invention relates to a container, and more particularly, to a container including features permitting the container to be stacked with containers of other sizes and shapes. The containers described and claimed herein permit more efficient, compact utilization of space, particularly in assembly areas where consistent container size, position and orientation are important factors in assembly line efficiency.
Stackable containers are well known in the art and come in all shapes and sizes. The regulatory weight limit for hand held containers has recently been reduced from 40 pounds to 35 pounds. Because of this reduction in hand held container weight limits, it has become more important for stackable containers to be as light as possible without sacrificing carrying capacity and versatility.
It is common for stackable containers to have either a flat bottom or a bottom with an outwardly-projecting grid pattern molded onto the bottom that defines a size and shape intended to mate with the size and shape of the opening of another container onto which the container is to be stacked. Stackable containers having a flat bottom lack versatility and do not allow the containers to be stacked on top of multiple smaller containers. For example, a single large flat bottom container cannot be stacked on top of six smaller containers. This restricts the order of stacking boxes, requiring larger boxes to always stack below smaller boxes.
Stackable containers having a molded grid pattern on the bottom tend to stick or hang-up on wheel-type conveyor systems, as well as, also producing an increased amount of conveyor chatter over that produced by a flat bottom container due to gaps between the ribs of the grid pattern which interact with the wheels of the conveyor system. In addition, the grid pattern, being simply molded onto the bottom of the container adds extra weight without increasing capacity. To remain within applicable weight limits, the carrying capacity of a stackable container having a grid pattern is somewhat reduced in comparison to a comparable flat bottom container.
Accordingly, there is a need for a stackable container that incorporates the benefits provided by both a flat bottom container and a container with a grid pattern, while eliminating the deficiencies of both containers.